I would like to disable the appointment drag, in the ultramontViewSingle, if more than one appointment are selected, just like outlook does it.
How can I do that?
Actually Outlook allows dragging an appointment selection that contains more than one member, you have to hold the control key down while dragging. You can prevent the selection of more than one appointment by setting the UltraMonthViewSingle.CalendarInfo.SelectTypeActivity property to 'Single'. If you need to allow multiple selection but prohibit dragging of more than one item, you can handle the UltraMonthViewSingle.ActivityDragging event and cancel it if more than one appointment is selected.